1. Field of Invention
The present invention relates to a disposable element comprising at least one first part, in which channel structures are recessed in the surface, and a second part sealingly covering said first part, with the larger part of the first part and/or of the second part being made rigid and/or being applied to a rigid carrier structure, and with these first and/or second parts, however, having at least one flexibly made region. The invention furthermore relates to a system for pumping and a method for pumping a liquid.
2. Description of the Prior Act
Disposable cassettes are already known from the prior art which are preferably used in the area of analytical technology. These cassettes have, for example, a plurality of layers which have rigid and flexible regions and which are made in one piece using two-component injection molding technology. The flexible regions can be made, for example, as pump chambers which can be pushed in by a corresponding actuator so that a fluid displacement takes place. A pump movement and/or also corresponding valve functions in the flexible regions is/are thus generated by mechanically driven plungers. Such mechanical interfaces, however, cause problems in the coupling of the disposable cassette to a corresponding machine. On the one hand, the so-called disposable cannot be placed completely smoothly on the machine part since there are always projections or recesses of the mechanical interfaces. On the other hand, a mechanical activation of the membranes can cause damage, for instance by the mechanical flexing movements of the flexible regions, which can result in the failure of the component. Such a corresponding disposable cassette is known, for example, from DE 102 39 597 A1.
U.S. Pat. No. 6,261,065 B1 furthermore describes a blood treatment system which is connected to a blood separation unit. This system has a cassette which has at least one pneumatically actuated pump.
U.S. 2007/0278155 A1 describes a mechanical fluid system having disposable cassettes which have flexible layers. Balance chamber systems for very precise liquid balancing are described which have first and second pump chambers and are separated by a flexible membrane. The inflow of a first fluid quantity into a first chamber of the balance chamber causes the displacement of the corresponding quantity of fluid from the second chamber. For this balance pump movement, a permanent magnet can be worked onto the flexible membrane which separates the two chambers and which can be moved by external electromagnets.
An electromagnetically operated membrane pump is furthermore known from DE 58 93 98 which is in particular provided for the aeration of aquariums. A magnetic armature is brought to oscillation by means of an electromagnet so that an air blast can be generated which can be introduced into the aquarium by means of a pressure pipe.
A drive for blood pumps is known from DE 199 63 306 A1 which is made in the form of a loudspeaker drive. In this connection, the drive has a magnet system and a mechanically sliding piston which is controlled by an absolute-position encoder and has windings which can be switched over and/or off, in which magnet system the piston can be fixed mechanically.
U.S. Pat. No. 4,459,977 relates to an apparatus for dialostic blood retroperfusion which can have an electromagnetically operated membrane pump.
U.S. Pat. No. 4,498,850 describes a pump having a pump chamber recess which is divided into two chambers by a magnetically actuable membrane and which is let into a pump chamber housing. A plurality of means are provided around the recess by means of which a magnetic field is applied so that the magnetically actuable membrane can be moved to trigger a pump movement.
WO 2006/123329 A2 describes a dispensing apparatus for a therapeutic fluid, in particular a dispensing apparatus for insulin, which is easy to handle and is preferably made in credit-card format. A membrane pump is described in connection with this apparatus which cooperates with two membrane valves which are each disposed upstream and are likewise activated electromagnetically.